Some fixed wing aircraft have leading edge high-lift devices such as droop nose devices or slats which are downwardly movable relative to the fixed structure of the wing from a stowed configuration to a deployed configuration. Deployment of such devices relative to the fixed structure causes a lateral gap to progressively open between a lateral edge of the high-lift device and the fixed structure. Such gaps can cause systems and structure within the fixed wing structure to become exposed to the risk of fire or debris ingress, or can alternatively impose an aerodynamic penalty on the aircraft.
Previous solutions have included a false floor attached to the fixed structure, but such a solution is not always practicable and also adds weight to the aircraft.